There are days that are seared into our communal memory. The day JFK was shot. September 11, 2001. But horrifically now our collective memories mark anniversaries of mass shootings. We add them to the calendars in our minds and struggle to get past them. June 14 is the six-month anniversary of Newtown. April 16 was the six-year anniversary of Virginia Tech. July 20 will be the one-year anniversary of Aurora. January 8 was the second year anniversary of Tucson. Each new day brings 30 new tragedies to mark. It is time now to end this scourge of senseless violence. Congress must act now to end...